Oswego, IL Tornado History — 188 Tornadoes Since 1950
How many tornadoes has Oswego, IL had?
Oswego has had 188 tornadoes on record within 25 miles since 1950, including 9 strong to violent (EF3+) tornadoes.
When was the most recent tornado near Oswego?
The most recent tornado within 25 miles of Oswego was an EF0 on March 19, 2025.
When is tornado season in Oswego?
July is historically the peak month for tornadoes near Oswego, with 36 on record. April through June account for 89 of the 188 tornadoes on record near Oswego.
At a Glance
Recent Tornado Activity Near Oswego
The last 20 years of confirmed tornadoes within 25 miles — 89 total, averaging 4.5 per year over this window.
Preliminary tornado reports near Oswego since December 29, 2025
These are 7 preliminary reports, not confirmed tornadoes. They have not yet been through an NWS damage survey, and are not counted in the confirmed totals above.
Preliminary reports are revised, merged, and sometimes withdrawn — historically about 23% are consolidated downward once surveys complete. Ratings are omitted until a survey assigns one.
Confirmed records above are complete through December 29, 2025. NOAA publishes the confirmed archive annually, so tornadoes after that date appear here first and move into the totals above once finalized.
NWS survey confirms an EF-1 tornado with peak winds near 105 mph... peak width of 300 yards... and path length of 22.4 miles. (LOT)
NWS survey confirms an EF-0 tornado with peak winds near 75 mph... peak width of 150 yards... and path length of 5.2 miles. (LOT)
NWS survey confirms a brief EF-0 tornado started just south of Wheaton College. Tornado was on the ground for 2 minutes or less. Peak width of 100 yards and winds of 75 (LOT)
An NWS damage survey confirmed an EF-0 tornado with peak winds of 85 mph... path length of 2.9 miles... and max width of 250 yards impacted Orland Park. (LOT)
Photo passed along of a tornado in Glen Ellyn... close to location of radar-indicated TDS. (LOT)
NWS survey confirms a preliminary EF-0 tornado. Peak winds of 80 mph... width of 150 yards... and length of 1.3 miles. (LOT)
An NWS damage survey confirmed an EF-1 tornado with estimated peak winds of 100 MPH... path length of 3.0 miles... and maximum width of 400 yards impacted Bartlett... c (LOT)
Within 25 miles of Oswego. Quoted text is the report narrative exactly as filed. Source: NOAA Storm Prediction Center preliminary storm reports, updated daily.
Tornadoes by Decade
Tornadoes by Enhanced Fujita Rating
F0–F5 ratings (pre-2007) are grouped with their EF equivalents. The Enhanced Fujita scale replaced the original Fujita scale in February 2007.
Tornadoes by Month
Casualties on Record Near Oswego
35 fatalities have been recorded within 25 miles of Oswego since 1950, across 5 events. 550 injuries have been reported across all events. 1990 was the deadliest year on record near Oswego.
The deadliest single event was an F5 on August 28, 1990, which caused 29 fatalities along a 16.4-mile track.
Notable Tornadoes Near Oswego
What the record shows near Oswego
The 2020s are the busiest decade on record so far near Oswego, with 65 of the 188 confirmed tornadoes within 25 miles. The Oswego record runs from the 1950s to today.
Of the tornadoes rated near Oswego, 154 reached EF0 or EF1 and 28 reached EF2 or stronger. The most intense on record near Oswego is rated EF5, of which 1 is logged. A further 6 near Oswego are unrated — events NOAA logged before a damage survey assigned a scale.
Across the last 20 years Oswego has averaged 4.5 confirmed tornadoes a year within 25 miles, 89 in total. 2023 was the busiest of them with 22, and 2 of those years passed with none at all.